Wireless mobile devices, especially those that are user-centric, are becoming common and essential in people's daily activities. Many business organizations are investing in mobile devices and the associated support infrastructures to improve the accessibility and effectiveness of their mobile workers. Currently, these mobile devices are mainly supported by the telecommunications infrastructures and the Internet. Examples of such mobile devices include mobile telephones and the Blackberry products developed by Research in Motion Limited (RIM). The mobile devices of the future, however, will likely be integrated mobile devices that provide a wide range of functions depending on the mobility environment which the user or subscriber is in at any moment. The environment could be the user's office building, the user's automobile, a public transportation system, a business premise or the user's home.
As society becomes increasingly mobile, people spend more time traveling to and from their offices, homes, and other destinations, typically in their cars or in other means of public transportation. In order to receive uninterrupted wireless support in different environments and the benefits provided by the various mobility systems, the characteristics concerning the user and the devices, both mobile and stationary, must be automatically updated and seamlessly available to the user at all times. This requirement is generally referred to as user global mobility.
A global mobility support environment enables a user to access the various mobile and stationary devices, and seamlessly operate the devices in different environments while still receiving the same services. These services might include the access to one's data, the availability of customized services, and the transparent access to subscribed mobility functions with the same user characteristics. In addition to supporting the various user devices, the mobility infrastructure must be capable of managing the various subscriber bases associated with the devices and the user.
For example, a sales person may be carrying a mobile device as the person leaves an office complex and enter a car. The mobile device would detect the change in the operating environment and switch to a different mobile user profile for the car environment, as well as enabling the mobile functions applicable to the car environment. Similarly, as the sales person approaches and enters the house, the same mobile device detects another change in the operating environment and switches to the user mobility profile for the home environment, and makes the home mobile functions available to the person.
While the number of different mobile devices being introduced in the market continues to increase, there has been little work in addressing the global mobility requirement for these devices to provide non-disruptive and seamless support services.
In the telecommunications field, global mobility is typically provided by an infrastructure that maintains a subscriber's information to the extent of supporting the subscribed services within the subscriber's operational domain. For mobile wireless services, the subscription details are part of an operational environment which is dynamically updated as the user's location changes. However, for the services that still depend on an wired infrastructure, the global mobility support for maintaining the dynamic nature of the user/subscriber information is still lagging far behind. Furthermore, the mobility support for some operational domains are so rudimentary that it is often difficult just to maintain the services intact when there is a change in the operating environment.
In the cellular telephone domains that use CDMA, GSM, and 3G technologies, the tracking and updating of a subscriber's mobility information is limited to the change in the subscriber's location relative to the radio plan in which the subscriber is operating. The information is usually based on a location area code and highly dependent on the accuracy of the mobile cellular density. The introduction of new radio technologies like WiMax improves the accuracy of the location change information, which in turn provides more acceptable mobility data on the subscriber. However, the telecommunication domains that use signal strength for computing the subscriber's position still lack a reliable method for deriving and updating the subscriber's mobility data when the subscriber enters a new operating environment.
From the foregoing it is appreciated that there exists a need for a global mobility infrastructure that can accept variety of mobility information and seamlessly support a diverse range of mobile devices in various operating environments.